• Title/Summary/Keyword: Bayesian Network

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Bayesian Analysis for Neural Network Models

  • Chung, Younshik;Jung, Jinhyouk;Kim, Chansoo
    • Communications for Statistical Applications and Methods
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    • v.9 no.1
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    • pp.155-166
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    • 2002
  • Neural networks have been studied as a popular tool for classification and they are very flexible. Also, they are used for many applications of pattern classification and pattern recognition. This paper focuses on Bayesian approach to feed-forward neural networks with single hidden layer of units with logistic activation. In this model, we are interested in deciding the number of nodes of neural network model with p input units, one hidden layer with m hidden nodes and one output unit in Bayesian setup for fixed m. Here, we use the latent variable into the prior of the coefficient regression, and we introduce the 'sequential step' which is based on the idea of the data augmentation by Tanner and Wong(1787). The MCMC method(Gibbs sampler and Metropolish algorithm) can be used to overcome the complicated Bayesian computation. Finally, a proposed method is applied to a simulated data.

A Study on the Sensitive Factors Influencing Acha Accident Using Bayesian Network (Bayesian Network를이용한 아차사고에 영향을 주는 민감요인에 관한연구)

  • Kim, Sang-Hyun;Shin, Yeon-Cheol;Moon, You-Mi
    • Proceedings of the Korean Society of Disaster Information Conference
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    • 2022.10a
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    • pp.162-163
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    • 2022
  • 기술발전에 따라 건설현장은 스마트 안전관리기술을 활용한 안전관리의 변화가 예고되고 있다. 중대재해처벌법 시행(22.1.27)이후 50인 이상 사망사고는87건(96명)으로 전년 동기109건(111명)대비22건(20.2%), 15명(13.5%)감소한 것으로 나타났다(국토교통부,2022). 반면에 단순비교지만 일본0.14%, 미국0.37%, 영국0.03%에 비해 한국의 재해율이 높으므로 다양한 안전관리활동의 과제가 남아 있다. 이에 아차사고 유형이 건설현장 특성간의 민감도모델 제시를 기반으로 근본적인 재해관리가 연구의 목적이다. 이를 이루기 위해 국토교통부의 아차사고 발굴데이터를 분석하여 유형을 분류하고, 공사기간, 공사규모, 신체부위 등의 요인간의 아차사고 민감성요인에 대하여 Bayesian Network를 이용하여 아차사고에 영향을 주는 모델링을 제시하고자 한다.

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Hierarchical Gabor Feature and Bayesian Network for Handwritten Digit Recognition (계층적인 가버 특징들과 베이지안 망을 이용한 필기체 숫자인식)

  • 성재모;방승양
    • Journal of KIISE:Software and Applications
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    • v.31 no.1
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    • pp.1-7
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    • 2004
  • For the handwritten digit recognition, this paper Proposes a hierarchical Gator features extraction method and a Bayesian network for them. Proposed Gator features are able to represent hierarchically different level information and Bayesian network is constructed to represent hierarchically structured dependencies among these Gator features. In order to extract such features, we define Gabor filters level by level and choose optimal Gabor filters by using Fisher's Linear Discriminant measure. Hierarchical Gator features are extracted by optimal Gabor filters and represent more localized information in the lower level. Proposed methods were successfully applied to handwritten digit recognition with well-known naive Bayesian classifier, k-nearest neighbor classifier. and backpropagation neural network and showed good performance.

User Adaptive Restaurant Recommendation Service in Mobile Environment based on Bayesian Network Learning (베이지안 네트워크의 학습에 기반한 모바일 환경에서의 사용자 적응형 음식점 추천 서비스)

  • Kim, Hee-Taek;Cho, Sung-Bae
    • 한국HCI학회:학술대회논문집
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    • 2009.02a
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    • pp.6-10
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    • 2009
  • In these days, recommendation service in mobile environments is in the limelight due to the spread of mobile devices and an increase of information owing to advancement of computer network. The restaurant recommendation system reflecting user preference was proposed. This system uses Bayesian network to model user preference and analytical hierarchical process to recommend restaurants, but static inference model for user preference used in the system has some limitations that cannot manage changing user preference and enormous user survey must be preceded. This paper proposes a learning method for Bayesian network based on user requests. The proposed method is implemented on mobile devices and desktop, and we show the possibility of the proposed method through experiments.

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Automatic Construction of Hierarchical Bayesian Networks for Topic Inference of Conversational Agent (대화형 에이전트의 주제 추론을 위한 계층적 베이지안 네트워크의 자동 생성)

  • Lim, Sung-Soo;Cho, Sung-Bae
    • Journal of KIISE:Software and Applications
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    • v.33 no.10
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    • pp.877-885
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    • 2006
  • Recently it is proposed that the Bayesian networks used as conversational agent for topic inference is useful but the Bayesian networks require much time to model, and the Bayesian networks also have to be modified when the scripts, the database for conversation, are added or modified and this hinders the scalability of the agent. This paper presents a method to improve the scalability of the agent by constructing the Bayesian network from scripts automatically. The proposed method is to model the structure of Bayesian networks hierarchically and to utilize Noisy-OR gate to form the conditional probability distribution table (CPT). Experimental results with ten subjects confirm the usefulness of the proposed method.

Online Learning of Bayesian Network Parameters for Incomplete Data of Real World (현실 세계의 불완전한 데이타를 위한 베이지안 네트워크 파라메터의 온라인 학습)

  • Lim, Sung-Soo;Cho, Sung-Bae
    • Journal of KIISE:Computer Systems and Theory
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    • v.33 no.12
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    • pp.885-893
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    • 2006
  • The Bayesian network(BN) has emerged in recent years as a powerful technique for handling uncertainty iii complex domains. Parameter learning of BN to find the most proper network from given data set has been investigated to decrease the time and effort for designing BN. Off-line learning needs much time and effort to gather the enough data and since there are uncertainties in real world, it is hard to get the complete data. In this paper, we propose an online learning method of Bayesian network parameters from incomplete data. It provides higher flexibility through learning from incomplete data and higher adaptability on environments through online learning. The results of comparison with Voting EM algorithm proposed by Cohen at el. confirm that the proposed method has the same performance in complete data set and higher performance in incomplete data set, comparing with Voting EM algorithm.

Nonlinear Networked Control Systems with Random Nature using Neural Approach and Dynamic Bayesian Networks

  • Cho, Hyun-Cheol;Lee, Kwon-Soon
    • International Journal of Control, Automation, and Systems
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    • v.6 no.3
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    • pp.444-452
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    • 2008
  • We propose an intelligent predictive control approach for a nonlinear networked control system (NCS) with time-varying delay and random observation. The control is given by the sum of a nominal control and a corrective control. The nominal control is determined analytically using a linearized system model with fixed time delay. The corrective control is generated online by a neural network optimizer. A Markov chain (MC) dynamic Bayesian network (DBN) predicts the dynamics of the stochastic system online to allow predictive control design. We apply our proposed method to a satellite attitude control system and evaluate its control performance through computer simulation.

Data mining approach to predicting user's past location

  • Lee, Eun Min;Lee, Kun Chang
    • Journal of the Korea Society of Computer and Information
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    • v.22 no.11
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    • pp.97-104
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    • 2017
  • Location prediction has been successfully utilized to provide high quality of location-based services to customers in many applications. In its usual form, the conventional type of location prediction is to predict future locations based on user's past movement history. However, as location prediction needs are expanded into much complicated cases, it becomes necessary quite frequently to make inference on the locations that target user visited in the past. Typical cases include the identification of locations that infectious disease carriers may have visited before, and crime suspects may have dropped by on a certain day at a specific time-band. Therefore, primary goal of this study is to predict locations that users visited in the past. Information used for this purpose include user's demographic information and movement histories. Data mining classifiers such as Bayesian network, neural network, support vector machine, decision tree were adopted to analyze 6868 contextual dataset and compare classifiers' performance. Results show that general Bayesian network is the most robust classifier.

Prediction of PM10 concentration in Seoul, Korea using Bayesian network

  • Minjoo Joa;Rosy Oh;Man-Suk Oh
    • Communications for Statistical Applications and Methods
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    • v.30 no.5
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    • pp.517-530
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    • 2023
  • Recent studies revealed that fine dust in ambient air may cause various health problems such as respiratory diseases and cancer. To prevent the toxic effects of fine dust, it is important to predict the concentration of fine dust in advance and to identify factors that are closely related to fine dust. In this study, we developed a Bayesian network model for predicting PM10 concentration in Seoul, Korea, and visualized the relationship between important factors. The network was trained by using air quality and meteorological data collected in Seoul between 2018 and 2021. The study results showed that current PM10 concentration, season, carbon monoxide (CO) were the top 3 effective factors in 24 hours ahead prediction of PM10 concentration in Seoul, and that there were interactive effects.